\\[-1.8ex] Soil Heterogeneity & $-$0.093$^{***}$ & $-$0.043$^{**}$ & $-$0.044$^{**}$ & $-$0.038$^{*}$ & $-$0.040$^{*}$ & $-$0.042$^{*}$ \\ 
  & (0.031) & (0.020) & (0.020) & (0.020) & (0.021) & (0.022) \\ 
\\[-1.8ex] 
Observations & 134,233 & 134,233 & 134,233 & 134,233 & 134,233 & 134,233 \\ 
R$^{2}$ & 0.010 & 0.019 & 0.023 & 0.050 & 0.106 & 0.196 \\ 
